Methods for removing a passivation film from a copper surface can include exposing the passivation film to a vapor phase organic reactant, for example at a temperature of 100° C. to 400° C. In some embodiments, the passivation film may have been formed by exposure of the copper surface to benzotriazole, such as can occur during a chemical mechanical planarization process. The methods can be performed as part of a process for integrated circuit fabrication. A second material can be selectively deposited on the cleaned copper surface relative to another surface of the substrate.
Legal claims defining the scope of protection, as filed with the USPTO.
1. A method of removing copper-containing particles from a dielectric substrate surface comprising copper-containing particles, the method comprising: contacting the dielectric substrate surface comprising copper-containing particles with a plurality of pulses of a vapor phase organic reactant at a pressure of 0.1 to 50 Torr without exposing the substrate to a plasma, wherein the vapor phase organic reactant interacts with the copper-containing particles to reduce a size of the copper-containing particles and form one or more volatile byproducts, and removing volatile byproducts from the dielectric substrate surface.
2. The method of claim 1 , wherein the substrate comprises a copper surface that has been subject to chemical mechanical polishing prior to contacting the dielectric substrate surface with the vapor phase organic reactant.
3. The method of claim 2 , wherein the chemical mechanical polishing comprises exposing the copper surface to benzotriazole.
4. The method of claim 1 , wherein volatile byproducts are removed from the dielectric surface by purging with an inert gas.
5. The method of claim 1 , wherein more than 70% of the copper-containing particles that were present on the dielectric substrate surface are removed from the dielectric substrate surface when the dielectric substrate surface comprising copper-containing particles is contacted with the plurality of pulses of the vapor phase organic reactant.
6. The method of claim 1 , wherein the vapor phase organic reactant is an alcohol, an aldehyde, or has the formula R—COOH, where R is hydrogen or a C1 to C3 alkyl.
7. The method of claim 1 , wherein the vapor phase organic reactant comprises a carboxylic acid.
8. The method of claim 1 , wherein the vapor phase organic reactant comprises formic acid.
9. The method of claim 1 , wherein the dielectric substrate surface is contacted with the vapor phase organic reactant at a temperature of 100° C. to 400° C.
10. The method of claim 1 , wherein the copper-containing particles have a longest dimension of up to 20 nm.
11. The method of claim 1 , wherein the copper-containing particles form a passivation layer on the dielectric substrate surface prior to contacting the dielectric substrate surface with the vapor-phase organic reactant.
12. A method for removing at least a portion of a passivation film comprising copper-containing particles from a dielectric substrate surface, the method comprising: exposing the passivation film to a plurality of pulses of a vapor phase organic reactant comprising an alcohol, an aldehyde or having the formula R—COOH, where R is hydrogen or a C1 to C3 alkyl at a pressure of 0.1 Torr to 50 Torr, wherein the passivation film was formed on the dielectric substrate surface by subjecting a copper surface on the substrate to chemical mechanical polishing, wherein the passivation film is not exposed to a plasma during exposure of the passivation film to the vapor phase organic reactant, and wherein the vapor phase organic reactant interacts with the copper-containing particles to reduce a size of the copper-containing particles and form volatile reaction byproducts; and removing volatile reaction byproducts from the dielectric substrate surface.
13. The method of claim 12 , wherein the passivation film is exposed to the vapor phase organic reactant at a temperature of 100° C. to 400° C.
14. The method of claim 12 , wherein the vapor phase organic reactant comprises carboxylic acid.
15. The method of claim 12 , wherein the vapor phase organic reactant comprises formic acid.
16. The method of claim 12 , wherein the passivation film is exposed to the vapor phase organic reactant in a plurality of cycles.
17. The method of claim 16 , wherein the passivation film is exposed to the vapor phase organic reactant at least 10 times.
18. The method of claim 12 , wherein removing comprises purging with an inert gas.
19. The method of claim 12 , wherein the copper-containing particles have a longest dimension of up to 20 nm.
20. The method of claim 12 , wherein chemical mechanical polishing comprises exposing the copper surface to benzotriazole.
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August 7, 2020
July 13, 2021
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